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Wind-driven effects on spectral amplitudes and seismic detection thresholds in a polar glacier setting
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  • Chris Carr,
  • Joshua Carmichael,
  • Erin Pettit,
  • Carl Tape
Chris Carr
Los Alamos National Laboratory

Corresponding Author:[email protected]

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Joshua Carmichael
Los Alamos National Laboratory
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Erin Pettit
Oregon State University
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Carl Tape
University of Alaska Fairbanks
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Abstract

Temporally variable environmental microseismicity and narrowband signals are both demonstrated to reduce the detectability of small seismic events. We investigate the influence of winter wind events on detection thresholds for a 3-sensor seismic network at the terminus of Taylor Glacier, Antarctica. As wind speeds increase, we observe higher spectral amplitudes across the frequency spectrum; however, some frequency bands are preferentially excited. Surprisingly, these spectral peaks shift frequencies through time. To determine detection thresholds, we implement a waveform injection routine wherein we add scaled waveforms to the datastream, and track changes in the size of the smallest scaled event that we can reliably detect. We thereby demonstrate a capability to quantify the size of the smallest detectable event in temporally variable signal environments. Lastly, we propose a method to forecast our ability to detect sources of a threshold size in measured noise conditions.